[Effect of afobazole on brain-ischemia-induced anxiety in rats].

The ability of afobazole, a selective anxiolytic to prevent the brain local ischemia-induced anxiety has been studied in experiments on rats. It is established that middle cerebral artery occlusion (MCAO) is accompanied by the development of anxiety, the degree of which increases with the duration of occlusion. Afobazole in a doze of 1 mg/kg administrated during 6 days after MCAO prevents the development of anxiety.

[Tropoxin and cerebrovascular effects of serotonin].

The effect of serotonin on the brain blood supply was studied in rats before and after ischemic damage. The ischemic damage, induced by ligation of the middle meningeal artery, markedly enhanced the constrictor effect of serotonin on the brain vessels. Tropoxin, a 5HT2 receptor blocker, completely eliminated these cerebrovascular effects of serotonin.

[Dopamine enhancement of the cerebral microcirculation in a local ischemic lesion].

The effect of dopamine on the local cerebral blood flow in parietal brain cortex region of rats was studied in conditions of local ischemia induced by middle cerebral artery occlusion. Registration of the local cerebral blood flow was performed on a ALF-21 laser doppler flowmeter ("Transonic System Inc.", USA).

[The different vascular reactions of intact and ischemic brain to adrenergic exposures].

Electrical stimulation of the cervical sympathetic ganglion and norepinephrine increase the tonus of the cerebral vessels in intact animals. This points to the significant role of adrenergic mechanisms in regulation of blood circulation in the brain. Local ischemic affection of the brain removes the vasoconstrictor effects of stimulation of the cervical sympathetic ganglion and norepinephrine.

[The effect of nimodipine on a local ischemic brain lesion].

A modified rat model of ischemic brain injury caused by ligation of the middle cerebral artery is proposed. The time course of morphological changes in brain tissues was studied and bilateral cerebral circulatory disorders, hypoxic cortical neurocytic damages followed by intracellular regeneration, as well as metabolic and structural changes not only in the cortical neurocytes, but in the conduction paths and synaptic terminals. Nimodipine had no effect on blood supply to the ischemic brain either early or late in ischemic brain injury after ligation of the middle cerebral artery.

[Local cerebral ischemia in rats induced by ligation of the middle cerebral artery].

A model of local cerebral ischemia induced by ligation of the middle cerebral artery, which is a modification of the techniques proposed by A. Tamura and others, is suggested. It allows experiments to be conducted on conscious animals with appraisal of the morpho-functional state of the nervous system.

[The cerebral blood circulation during hypokinesia under the influence of hypercapnia, hypotonia, GABA and neurosensory stimulation].

We studied the formation of vasomotor reflexes in hypokinesia and responses of the brain vessels to the action of GABA, hypotension, and hypercapnia. We found that the response of the brain vessels to GABA is delayed and the mechanisms which supported an adequate cerebral vasculation are distorted in hypotension. At the same time the disturbance of the reflectory reaction of the brain vessels in the course of forming the vasomotor reflexes and the absence of significant changes in response to GABA were noticed.

[The central vascular and metabolic effects of pyroglutamic acid].

The ability of pyroglutamic acid, a cyclic glutamic acid derivative, to increase cerebral blood flow, to decrease the resistance of brain vessels, and to relax the isolated grafts of cerebral arteries has been demonstrated. Pyroglutamic acid markedly stimulated brain metabolism: increased glucose uptake and utilization by cerebral tissues and decreased brain lactate dehydrogenase activity.

[The antihypoxic activity of endogenous cyclic derivatives of gamma-aminobutyric acid].

Pirrolidone-2, gamma-butyrolacton, succinic anhydride were found to possess pronounced antihypoxic activity that manifested itself in their ability to decrease the level of lactic acid accumulated during hypoxia. Pirrolidone-2 and succinic anhydride increase succinic dehydrogenase activity in vitro. At intraperitoneal administration the above mentioned compounds lead to lactate dehydrogenase activity inhibition under normal conditions while during circulatory hypoxia they stimulate lactate dehydrogenase reaction promoting the maintenance of energy balance of the cerebral tissue at the appropriate level.

[Effect of 2-pyrrolidone and gamma-butyrolactone on the rate of 14C-leucine incorporation into the proteins of different brain structures and of their arterial tissues].

The ability of cyclic GABA and GHBA derivatives--2-pyrrolidone and gamma-butyrolactone--to increase markedly the inclusion of 14C-leucine in the proteins of hypothalamus and cerebral arteries both normally and in condition of cerebral blood supply disturbances produced by unilateral 20 min ligation of a common carotid artery has been demonstrated.

[Contractile capacity of isolated flaps from the aorta of rats with stable arterial hypertension caused by the prolonged administration of cerebrosides].

A study was made of the contractility of smooth muscle cells of abdominal aorta strips of noninbred white rats with stable arterial hypertension induced by protracted intraperitoneal injection of cerebrosides isolated from cattle brain. It was demonstrated that as compared with normotensive animals, smooth muscle cells of the animals' arteries are characterized by the increased influx of extracellular calcium via slow potential-dependent calcium channels and hypersensitivity to noradrenaline and serotonin.

[Role of GABA and its derivatives in regulating cerebral circulation].

GABA, its derivative -- gamma-hydroxybuturic acid and metabolite --succinic acid have a pronounced dilatatory activity on cerebral circulation in various brain parts. GABA increases cerebral circulation by 25.3%, gamma-hydroxybutyric acid by 35.